At present, backlight modules of liquid crystal display devices are mainly divided into a direct-down type and an edge-in type. An edge-in type of backlight module generally adopts a light guide plate. In this case, the light guide plate enables a linear light emitted from a backlight source to be converted into an area light. Therefore, the light guide plate is now a key part in a display device adopting an edge-in type of backlight module.
In recent years, with rapid development of the display field, “super-thinness”, “highlighting”, and “narrow frame” have become essential requirements of the high-end display market. But this will also cause some optical problems. For example, in order to improve brightness of the display, microstructure processing is performed on the light guide plate of the backlight source to increase the optical energy utilization. However, this can easily give rise to problems such as “intersecting light beams”, for instance, intersecting light beams caused by condensation of a V-groove structure on a light exit surface of the light guide plate. Besides, due to a reduced size of the frame and inadequacy number of LED lamps, light emitted from an LED light source will enter an image region before it is sufficiently mixed. This has gone beyond the adjustable brightness range of nodes, which leads to brightness nonuniformity in front of the lamps in the image display region.